Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0029713 (immaturity)
 4,335 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The clinical response and changes in water and salt homeostasis during ORT was studied in 15 infants less than 2 months old (range 2-50 days) with acute diarrhoea. Eight patients were neonates and 7 were 1-2 months old. The oral rehydration solution contained 60 mmol sodium per litre. All patients except one were successfully rehydrated. The fluid retention was significantly higher in neonates and young infants than in infants above 3 months of age treated in the same way. One patient in the group of neonates who had a normal sodium level on admission developed hypernatremia with a sodium level of 162 mmol/l 36 hours after the start of ORT. The urinary sodium excretion was lower in the neonates than in the young infants. The results show that neonates and young infants have a lower capacity than older infants to excrete water and salt and therefore run a great risk of developing fluid and salt retention during ORT. The risk is most pronounced in neonates who, due to immaturity of the renal function, are unable to excrete excess fluid and salt.
 ...
PMID:Oral rehydration therapy in neonates and young infants with infectious diarrhoea. 330 Jan 47

Centrally-mediated responses to plasma hyperosmolality include compensatory drinking and pituitary secretion of vasopressin and oxytocin in both adult and neonatal rats. However, the anorexia that is produced by plasma hyperosmolality in adult rats is not evident in neonates, perhaps due to functional immaturity of osmoresponsive hindbrain circuits. To examine this possibility, the present study compared treatment-induced brain expression of the immediate-early gene product c-Fos as a marker of neural activation in adult and two-day-old rats after subcutaneous injection of 2 M NaCl (0.1 ml/10 g body weight). This treatment produced marked hypernatremia in adult and two-day-old rats without altering plasma volume. Several brain regions (including components of the lamina terminalis, the paraventricular and supraoptic nuclei of the hypothalamus, and the area postrema) were activated to express c-Fos similarly in adult and two-day-old rats after 2 M NaCl injection, consistent with previous reports implicating a subset of these regions in osmotically-stimulated drinking and neurohypophyseal secretion. In contrast, other areas of the brain that were activated to express c-Fos in adult rats after 2 M NaCl injection were not activated in neonates: these areas included the central nucleus of the amygdala, the parabrachial nucleus and catecholamine cell groups within the caudal medulla. This study demonstrates that certain brain regions that are osmoresponsive in adult rats (as defined by induced c-Fos expression) are not osmoresponsive in two-day-old rats. When considered in the context of known differences between the osmoregulatory capacities of adult and neonatal rats, our results are consistent with the idea that osmoresponsive forebrain centres are primarily involved in osmotically-stimulated compensatory drinking and neurohypophyseal secretion, whereas osmoresponsive regions of the hindbrain are important for concomitant inhibition of feeding and gastric emptying.
 ...
PMID:Central c-Fos expression in neonatal and adult rats after subcutaneous injection of hypertonic saline. 921 75